[GHA] Skip loading ext-relay when it's not available

Author: nicolas-grekas

.github/workflows/unit-tests.yml

@@ -59,6 +59,8 @@ jobs:
           git config --global init.defaultBranch main
           git config --global advice.detachedHead false
 
+          (php --ri relay 2>&1 > /dev/null) || sudo rm /etc/php/*/cli/conf.d/20-relay.ini
+
           COMPOSER_HOME="$(composer config home)"
           ([ -d "$COMPOSER_HOME" ] || mkdir "$COMPOSER_HOME") && cp .github/composer-config.json "$COMPOSER_HOME/config.json"